Water Heating Systems

Seisco Tankless Heaters

Electric Water Heaters

Four Chamber Seal Replacement

Before beginning, it would be advisable to check the four bolts that hold the two chamber halves together before attempting the replacement of the seal. If these bolts can be tightened to stop a leak, major replacement costs may be avoided. Also, the replacement of the inter chamber seal is seldom the correct approach, because it is more labor intensive and may be less cost effective than replacing the entire chamber body.

It will be necessary to remove the entire heater from the wall and the control board from the chamber assembly.

Required Tools

• Large & small Phillips screw drivers
• battery powered volt meter
• rag, bucket
• two pipe wrenches
• needle nose pliers
• heat sink compound
• Teflon tape pipe sealer

Warning: To avoid electrical shock, make sure that the all of the power is off to the heater before attempting to remove the old chamber seal and while installing the new seal.

1. Turn off all the power to the heater. Confirm the power is off with a voltmeter, even if the status light (or LED) on the control board is off. There may be multiple breakers powering your model heater.
2. Open a hot water faucet nearby. While the water is running, turn off the water supply to the heater. This will help siphon some of the water out of the heater.
3. Using a large Phillips screw driver, remove the six screws from the bottom clean out plates on the under side of the heating chambers to drain the remaining water from the heater into a bucket.
4. Remove the control board according to procedure A. Changing The Control Board.
5. Using two pipe wrenches, disconnect the incoming water line threaded onto the top of the inlet fitting. Use the rag to prevent any water dripping or spraying, which should be very little if any.
6. Back out the AC power wires through the right side of the metal base pan.
7. Remove the entire heater assembly from the wall by removing the 4 mounting screws.
8. Remove the four Phillips head screws in the back of the assembly that hold the heating chamber to the metal base pan.
9. Remove the four bolts that hold the two chamber assemblies together and replace the inter seals.
10. At this point, if necessary, replace the right or the left chamber half. Make sure to use the removal procedures for the inlet tubes, guides, seals and adapters to reuse if replacing the right side chamber assembly. Remove the outlet tube and seal if replacing the left side chamber assembly.
11. Re-assemble in the reverse order.
12. Wrap the Teflon tape pipe sealer around the threads of the inlet and outlet fittings before reconnecting to the inlet and outlet water lines. Do not use Plumber’s Putty or Pipe Dope on the threads of the inlet and outlet fitting connections. If using CPVC or PVC primer and glue, avoid contact of these substances with the inlet and outlet fittings on the heater. These substances are highly corrosive and can damage the inlet and outlet fittings. Leaks may occur as a result and cause severe damage to the heater.
13. Turn on the water and check for leaks.
14. Turn on the power to the heater.

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